''Microcosmodon'' is a

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

from the

Paleocene The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

. It was a member of the extinct order

Multituberculata Multituberculata (commonly known as multituberculates, named for the multiple tubercles of their teeth) is an extinct Order (biology), order of rodent-like mammals with a fossil record spanning over 130 million years. They first appeared in the M ...

, and lies within the suborder

Cimolodonta Cimolodonta is a clade of Multituberculata, multituberculate mammals that lived from the Cretaceous to the Eocene. They probably lived something of a rodent-like existence until their ecological niche was assumed by true rodents. The more basal ...

and family

Microcosmodontidae Microcosmodontidae is a poorly preserved family of fossil mammals within the extinct order Multituberculata. Representatives are known from the Lower Paleocene of North America. The family is part of the suborder Cimolodonta. Other than that, the ...

. The genus ''Microcosmodon'' was named by G.L. Jepsen in 1930.

Species

The species ''Microcosmodon arcuatus'' was named by P.A. Johnston and R.C. Fox in 1984.

Fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

remains have been found in the Puercan (Paleocene)-age

strata In geology and related fields, a stratum (: strata) is a layer of Rock (geology), rock or sediment characterized by certain Lithology, lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by v ...

Rav W-1 of

Saskatchewan Saskatchewan is a Provinces and territories of Canada, province in Western Canada. It is bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and to the south by the ...

, Canada. The

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

is in the

University of Alberta The University of Alberta (also known as U of A or UAlberta, ) is a public research university located in Edmonton, Alberta, Canada. It was founded in 1908 by Alexander Cameron Rutherford, the first premier of Alberta, and Henry Marshall Tory, t ...

collection. When alive, the creature weighed about the same as a well-fed mouse (about 30 g). The

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

''Microcosmodon conus'' was named by G.L. Jepsen in 1930. Remains have been found in the Tiffanian (Paleocene)-age strata of the Polecat Bench Formation of

Wyoming Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho t ...

(United States) and Saskatchewan, Canada. This species would have weighed around 15 g. The species ''Microcosmodon harleyi'' was named by A. Weil in 1998. Remains have been found in the Puercan (Paleocene)-age strata of the Tullock Formation in

Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...

(USA). "The presence of the new species suggests that microcosmodontine species richness in the Western Interior was as high at the beginning of the Paleocene as at its end," (Weil, 1998). The species would have weighed about 20 g. The species ''Microcosmodon rosei'' was named by D.W. Krause in 1980. Remains have been found in the Clarforkian (Paleocene)-age strata of the Willwood Formation of Wyoming. This species weighed a fairly standard mouse-sized 25 g+. The species ''Microcosmodon woodi'' was named by R.C. Holtzman and D.L. Wolberg in 1977. It is also known as ''Eucosmodontid woodi'' (Weil 1998). Remains have been found in the Middle Paleocene-age strata of Montana and

North Dakota North Dakota ( ) is a U.S. state in the Upper Midwest, named after the indigenous Dakota people, Dakota and Sioux peoples. It is bordered by the Canadian provinces of Saskatchewan and Manitoba to the north and by the U.S. states of Minneso ...

(USA) and

Alberta Alberta is a Provinces and territories of Canada, province in Canada. It is a part of Western Canada and is one of the three Canadian Prairies, prairie provinces. Alberta is bordered by British Columbia to its west, Saskatchewan to its east, t ...

, Canada. However, Weil A. (1998) found that this material "does not belong to this genus or subfamily."

References

* Weil (1998), "A new species of ''Microcosmodon'' (Mammalia: Multituberculata) from the Paleocene Tullock Formation of Montana, and an argument for the Micrcosmodontinae". ''PaleoBios'' 18. * Krause (1980), "Multituberculates from the Clarkforkian Land-Mammal Age, late Paleocene-early Eocene, of western North America". ''J. Paleont.'' 54(6), p. 1163-1183. *Jepsen (1930), "Stratigraphy and paleontology of the Paleocene of northeastern Park County, Wyoming". ''Proceedings of the American Philosophical Society'' 69(1), p. 463-528. *Holtzman & Wolberg (1977), "The Microsmodontinae and ''Microcosmodon woodi'', new Multituberculata taxa (Mammalia) from the Late Paleocene of North America". ''Sci. Publ. of the Sci. Mus. of Minnesota'' 4(1), p. 1-13. *Kielan-Jaworowska Z & Hurum JH (2001), "Phylogeny and Systematics of multituberculate mammals". ''Palaeontology'' 44, p. 389-429. *Johnston & Fox (1984), "Paleocene and Late Cretaceous mammals from Saskatchewan, Canada". Palaeontogr. Abt. A: Paläozool., Stratigr. 186, p. 163-222. *Much of this information has been derived fro

MESOZOIC MAMMALS:

Eucosmodontidae Eucosmodontidae is a poorly preserved family of fossil mammals within the extinct order Multituberculata. Representatives are known from strata dating from the Upper Cretaceous through the Lower Eocene of North America, as well as the Paleocene t ...

and

Taeniolabidoidea Taeniolabidoidea is a group of extinct mammals known whose fossils can be found in North America and Asia. They were the largest members of the extinct order Multituberculata, as well as the largest non-therian mammals. '' Lambdopsalis'' even pr ...

, an Internet directory. {{Taxonbar, from=Q767786 Cimolodonta Paleocene mammals Paleocene genus extinctions Extinct mammals of North America Prehistoric mammal genera